Note 13 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Allowance for doubtful accounts receivable	$ 46	$ 48
Accrued risk reserves	1,625	1,433
Accrued expenses	5,926	5,504
Financial reporting depreciation in excess of tax depreciation	3,966	6,340
Stock based compensation	666	959
Non-refundable entrance fees	89	103
Obligation to provide future services	530	580
Deferred revenue	5,425	3,480
State net operating loss carryforwards	0	5,762
Operating lease liabilities	52,870	0
Total gross deferred tax assets	71,143	24,209
Less: Valuation allowance	0	(5,762)
Deferred tax assets less valuation allowance	71,143	18,447
Unrealized gains on marketable securities	(32,638)	(28,032)
Deferred gain on sale of assets, net	(2,094)	(2,146)
Book basis in excess of tax basis of intangible assets	(2,063)	(1,748)
Book basis in excess of tax basis of securities	(2,172)	(1,889)
Long–term investments	(3,318)	(3,182)
Operating lease assets	(52,870)	0
Total deferred tax liabilities	(95,155)	(36,997)
Net deferred tax liability	$ (24,012)	$ (18,550)